Comstock/Thinkstock(MYRTLE BEACH, S.C.) -- Four people have been bitten by a marine animal or animals in the water off Myrtle Beach, S.C., according to fire rescue officers.

The victims were reportedly bitten Thursday on their feet and calves. One witness said that a victim was in chest-deep water with his girlfriend when the attack happened.

“There were about five large indentations on his calf. The blood was pouring down to his ankle and he had five sets of teeth marks,” witness John Gonas told Carolina Live.

Three of the victims were taken by Emergency Medical Services to Myrtle Beach’s Grand Strand Regional Medical Center.

Horry County fire officials cannot say whether the bites were caused by a shark, although a lifeguard reportedly said that he was almost certain it was a shark attack.

“Nobody saw them. Even the guys that got bit didn’t see it,” lifeguard Denny Starr told the Charlotte Observer. “They’re definitely shark bites. One guy’s foot was opened up. The other had a full mouth print around his leg.”

Shark bites are more common near piers, because of bait in the water. These victims, however, were not near a pier.

A 25-year-old man was bitten by a shark on the same beach earlier this month. He is expected to make a full recovery.